The present invention relates to a pressure cylinder with a variable configuration axis.
In particular, the present invention relates to a pressure cylinder which can be used in contact with a movable supporting surface, generally a cylindrical surface, for imparting to this latter a determined pressure distributed in a substantially uniform manner along a line of contact.
The formation of a pressure cylinder of the type described above does not, in general, present any problem in cases in which the said line of contact is of relatively short length. In this case, in fact, the deflection of the axis of the pressure cylinder and, therefore, of the said line contact, is substantially nil and, in any case, not such as to afford significant variations in pressure from point to point along the said line of contact.
The situation is considerably complicated if the said line of contact has a relatively great length since, in this case, both the deflection of the cylinder under its own weight, and the deflection of the said contact surface, afford an imperfect contact between this latter and the pressure cylinder. Consequently, the contact pressure is not uniformily distributed along the said line of contact, but varies from point to point along this, normally according to a complex law having a minimum at mid point of the pressure cylinder. When it is required that this minimum be above a certain value, it becomes necessary to apply to the cylinder a pressure corresponding to a mean pressure value along the said contact line which is many times greater than the value of the said minimum.